The money she is paying on that unit would accrue in equity on an annual basis.

Although the county has a purchase amount + accrued taxes, was there room to make a lower offer that the county accepted or were they strict with the taxes owed purchase amount? 

Zillow, along with their third party vendor, whoever it is, is running an interest accruing scam. 10 days for an ACH payment to hit?

The interest continues to accrue on each year's taxes.

In my calculation for net income, I accrue for tax/interest/insurance to spread these costs over the year so that we have a smooth net income amount to go off of.

Any rights of Landlord that accrued prior to cancellation will survive such cancellation.COST OF SERVICES AND REIMBURSEMENT.

@Trey Crusey, interest accrues not just on the taxes, but also on a portion of the overbid. 

My parents (father) took out a reverse mortgage approximately 5 years ago and have accrued about $160k in total. 

If it involves carrying out the hands-off buy-and-hold investing model largely espoused by this website, where you but a bunch of leveraged properites, hire a property manager to take your worries away, and slowly watch the returns accrue, well, that's the dream Clayton Morris sold and people with even minimal experience in C and D property classes understand it tends not to work so well down in the lower end of the rental spectrum.If you're talking about being the kind of landlord I am, well, you're going to be fixing a lot of stuff yourself, waiting for a lot of people to show up who don't, dealing personally with tenants who have real problems, and most definitely not living any sort of aspirational life most people would want.To just give you a taste of this life, right now, a local buddy of mine who is also in the business is in the hospital.

Again this is typically the ranges I use/recommend  and worst case scenario if you over compensate for some expenses you'll start to accrue large operating accounts, which is way better than finding yourself cash poor.